Pneumatic safety stop for die closures



Dec. 5, 1950 L. H. MORIN v PNEUMATIC SAFETY STOP FOR DIE CLOSURES Filed June 10, 1947 INVENTOR 100/5 Mom/v ATTORNEY Patented Dec. 5, 1950 UNITED STATES PNEUMATIC SAFETY STGP FOR DIE CLOSURES Louis Morin, Bronx, N. Y.

Application June 10, 1947, Serial No. 753,674

I 3 Claims. I

This invention relates to die casting machines employing pairs of dies movable toward and from each other. More particularly, the invention is concerned with a pneumatically actuated safety stop mechanism whereby the failure of either die to complete its full stroke, or movement into closed position, will set the safety stop mechanism into operation to stop operation of the machine, and further to stop discharge of casting material from the goosene'ck or other source of supply. The novel features oi the invention will be best understood from the following descriptions when taken together with the accompanying drawing in which certain embodi ments of the invention are disclosed, and in which the separate parts are designated by suitable reference characters in each of the views; and in which:

Fig. 1 is a partial sectional view through the die guides and operating mechanism of a casting machine, showing my improved safety stop mechanism in part.

Fig. 2 is a diagrammatic or schematic outline of such parts or mechanisms of a machine as deal with the stop control governed by said safety stop mechanism; and

Fig. 3 is an enlarged detailed View of one of the air valves, showing the same in closed position.v

In illustrating one adaptation and use of my invention, I have indicated in Fig. 1 of the drawing, part of a hydraulically actuated die casting machine, such as more fully disclosed in a com panion application, Serial Number 753,190, filed June 7, 1947.

In Fig. 1, I have shown at it, part of a frame of a machine, in which is arranged two similar die guides II and i2. In the guides H and :2 are slidably mounted die supporting members i3 and i4 supporting on their adjacent surfaces, dies and it which are detachable with respect to the members it and It, as by way of plates ll having screws 19 and 20.

At the outer end portions of the members It and it are heads 2i and 22 with which are adjustably supported stop screws 23 and 2% adapted to strike blocks 25 and 28 on the guides ii and I2 in forming a check for inward movement of the dies, and in this respect, said blocks may be composed of cushioning material. Also supported on the heads 2! and 22 are brackets 21 and 213 in which are adjustably supported control screws 29 and 39.

Detachably coupled with the forked extensions 3| and 32 on the frame, are hydraulic cyl- 2 inders 3333, both of which are of the same construction, and in said cylinders are arranged pistons or plungers 343 i' adapted to strike blocks 35-45, secured to the outerhead ends 2i and 22 of the members I 3 and id in movcmerit of the dies into closed position. The pistons or plungers' 34-3 are actuated by oil, under pressure, introduced into the cylinders through pipes 3636", both of which communicats with a valve diagrammatically shown at 3? in Fig. 2, which controls the feed oi oil under pressure to the cylinders.

In Fig. 2, a pump. 38 is shown to pump oil from a supply tank 39 through the valve 3? or back into the tank through a return pipe 46, the latter operating also. as a drain for the pipes 36-36. Extending out from the valve 31'? is a plunger carrying a roller 4|, by means of which the valve element may be actuated through a suitable mechanism of the machine which forms no part of my present invention and, therefore, is not shown.

In Fig. 2 of the drawing, I have diagrammatically outlined at 42, the pot or molten metal container of the machine in which is swingably mounted the gooseneck 43, the nozzle 44? of which is adapted to be brought into engagement With the dies, one of which is indicated at i5, in Fig. 2. Communicating with the. gooseneck d3 is an air line 45 in which is disposed an electrically controlled and operated valve ie, so that as and when the circuit to the valve 18 is broken, the air supply to the pipe it. will be shut off, preventing discharge of molten. metal to the gooseneck. 7

Supported on top of the guides ii and iii are valve devices 41 and 48 in which are mounted plungers i9 and 5!! normally held in outwardly extended positions. by springs 5i and 52. An air supply pipe 53 has communications centrally of the cylinders 4'! and it, as at 54 and 55, at

the end of the cylinders communicate pipes 53' and 51., the latter having one. communication, as at 58, with a pipe 59. One end of the pipe 59 extends to a diaphragm valve fill-and the other end. to a plunger pin operating device 65, the pin 62 of which is adapted to support an arm 53 in such position as to maintain the goosenec'k 33 with the nozzle 44 out of engagement with the dies. The pin 62 thus renders a cam 6 normally controlling operation of the lever 63, inoperative. The diaphragm valve Bi! has a plunger pin for actuating a suitable switch, as at 3G, to break the circuit through the wires 6.! and 6 8. In Fig. 2, 69 diagrammatically illustrates the motor for actuating the machine. In Fig. 1, means such as the hydraulic actuated plungers 35-34 are shown for moving the dies into closed position, other means being employed for moving the dies into open position, but such means is not shown, as it forms no part of the present invention but is clearly shown in the application above referred to.

The present invention is concerned primarily with movement of the dies into abutting engagement with each other, and in holding the dies in such engagement. This is accomplished by the hydraulically actuated plungers and in inward movement of the dies by the plungers. The control screws 29 and 3B strike the plungers 49 and 59 and advance said plungers inwardly to a point where they cover the discharge ports 54, and 55, providing each die has fully completed its closing movements. Immediately after the dies have completed the closing movement thereof a blast of air pressure is admitted into the pipe 53, and if the plungers 49 and 5B are in their closed position, this air will be checked at the valves M and t8. However, should either one of the dies fail to complete its inward or closing movement, this would result in failure of the associated plungers 59 and 53 to close the port 5 3 and 55, thus allowing air under pressure to pass through one of the pipes 55 and 5? and into the pipe 58 and thus extend to the valve '86 and the device 6i. It will appear that operation of the valve 58 will break the circuit through the switch 6%, stop the motor, and at the same time,

release the valve 46 to close the same, preventing air from timely entering the pipe 55. The actuation of the device 6! provides a further safeguard in maintaining the nozzle 416 out of engagement with the dies.

The control screws 29 and as provide a fine adjustment for the actuation of the plungers is and 59 so that closing movement of the dies can be carefully gauged.

In operation of dies of the type and kind under consideration, it is also possible that some foreign material may present itself between adjacent surfaces of the dies preventing the dies from performing the full stroke which would insure com-- plete closure of the dies. It is also possible that some mechanism may present itself between the head ends of the members It and I4, and the guides therefor, which would check inward movement, or further that the hydraulic cylinders may fail to perform their intended function. With my improved safety stop control of die closure, operation of the machine will be checked and discharge of casting material stopped until necessary repairs have been made to facilitate proper functioning of the dies.

It will be understood that my invention is applicable to machines of the general type and class under consideration wherein a pair of dies are movable toward and from each other.

In machines of the type and kind under consideration it has been customary to employ control switches which are constantly operated in each cycle of operation of the machine. This results in a wear which requires replacement of the switches from time to time. One of the distinctive features of my invention resides in the fact that during normal operation of the machine, the switch 65 remains closed and the switch operating mechanism idle. It is only when a die fails to properly close that said mechanism and switch are put into operation.

Having fully described my invention, what I 4 claim as new and desire to secure by Letters Patent is:

1. In a pneumatic safety stop mechanism for stopping the operation of a die-casting machine upon failure of either one of a pair of movable dies in said machine to complete its closing movement, said dies being slidably supported in guides on the frame of the machine and being movable toward and away from each other, the combination of a switch controlling the operation of the machine, and operated by a pneumatic means a pneumatic control valve supported in a fixed position on each of the guides, said control valves normally being open and having an outlet port connected to the pneumatic operating means of the switch and an inlet port connected to means for intermittently supplying air under pressure from a common source to each of said valves, and valve-operating means carried by each of the movable dies, each of said vaive-operating means carried by the respective dies engaging with and closing one of said control valves upon movement of its respective die to closed position.

2. In a pneumatic safety stop mechanism for stopping the operation of a die-casting machine upon failure of either one of a pair of movable dies in said machine to complete its closing movement, said dies being slidably supported in guides on the frame of the machine and being movable toward and away from each other, the combination of an electric motor for actuating the machine, an electrically operated valve controlling the admission of air under pressure to means for discharging molten metal to the dies, a circuit connecting said motor and said valve to a source of electrical energy, a switch in said circuit, said switch being normally closed and being operable by pneumatic means to open said circuit, a pneumatic control valve supported in a fixed position on each of the guides for the dies, said control valves normally being open and having an outlet port connected to the pneumatic operating means of the switch and an inlet port connected to means for intermittently supplying air under pressure from a common source to each of said valves, and valve-operating means carried by each of the movable dies, each of said valve-operating means carried by the respective dies engaging with and closing one of said control valves upon movement of its respective die to closed position.

3. In a pneumatic safety stop mechanism for stopping the operation of a die-casting machine upon failure of either one of a pair of movable dies in said machine to complete its closing movement, said dies being slidably supported in guides on the frame of the machine and being movable toward and away from each other, the combination of an electric motor for actuating the machine, a circuit connecting said motor to a source of electrical energy, a switch in said circuit, said switch being normally closed and being operable by pneumatic means to open said circuit, a pneumatic control valve supported in a fixed position on each of the guides for the dies, said control valves normally being open and having an outlet port connected to the pneumatic operating means of the switch and an inlet port connected to means for intermittently supplying air under pressure from a common source to each'Hf'said valves, and valve-operating means carried by each of the movable dies, each of said valve-operating means carried by the respective dies engaging with and closing one of said control valves 55 6 upon movement of its respective die to closed Number Name Date position. 1,759,537 Buckbee et a1 May 20, 1930 LOUIS H. MORIN. 1,815,361 Morris et a1 July 21, 1931 1,895,596 Wagner Jan. 31, 1933 7 REFERENCES CITED 5 1,950,864 Schultz Mar. 13, 1934 The following references are of record in the 1,931,330 Wagner 20, 1934 file of this patent: gagner :92- 2 ern e UNITED STATES PATENTS 2,197,473 Jackson et a1. Apr. 16, 1940 Num er Name Date 10 2,224,977 Morin Dec. 17, 1940 8, 1 V eder Apr- 1902 2,310,261 Schwarzhaupt et a1. Feb. 9, 1943 1,662,750 Kaufmann Mar. 13, 1928 

